The present invention relates to a treatment device for subjecting an object to a desired treatment after washing the object, a laser annealing device for annealing an object by laser irradiation, a manufacturing apparatus provided with the treatment device or the laser annealing device, and a manufacturing apparatus for a flat display device.
In manufacturing processes for manufacturing an array substrate of an liquid crystal display panel for use as a flat display device, such as a film forming process, etching process, laser annealing process, etc., substrates are washed before pretreatments in order to secure the cleanness of the substrates, in general. To attain this, a manufacturing apparatus comprises a plurality of treatment devices for carrying out the individual processes and a washing device provided independently of the treatment devices. The substrates, to-be-treated objects, are transported between the washing device and the treatment devices by means of a truck or an AGV (automatic transportation vehicle) in a manner such that they are set in a cassette.
In the case where the treatment devices and the washing device are arranged separately, however, the entire manufacturing apparatus requires a wide installation space, and the substrates are transferred between the devices. Therefore, the transportation takes so much time that the substrates may possibly be soiled and the lead time is long.
Further, the treatment time or Q-time requires management, and introduction of the substrates into each preceding stage is restricted by conditions for each succeeding stage, so that the processing operation of the manufacturing apparatus is complicated as a whole.
In a known laser annealing device for the laser annealing process, a laser is applied to non-single crystalline (amorphous) silicon film formed on a substrate to anneal the silicon layer, thereby forming a polycrystalline silicon film. If the annealing process is carried out in an ambient atmosphere with a high oxygen concentration, for example, in the laser annealing device, the resulting polycrystalline silicon film may possibly be poor in properties.
To avoid this, a novel annealing device is developed and described in Jpn. Pat. Appln. KOKAI Publication No. 9-275080, for example. This device is designed so that a substrate inlet chamber, transfer chamber, annealing chamber, transfer chamber, and substrate outlet chamber are connected in succession by means of gate valves. In this device, a vacuum atmosphere or nitrogen atmosphere is defined in an annealing chamber by means of a vacuum exhaust system. In the annealing chamber, substrates are preheated and irradiated with a laser for annealing.
In the laser annealing device constructed in this manner, however, the vacuum exhaust system is needed to control the atmosphere in the annealing chamber, so that stabilizing the atmosphere takes a lot of time, and each chamber must be composed of the so-called vacuum chamber that is highly airtight, thus entailing an increase in manufacturing costs. Since a large number of chambers are connected in the device, moreover, the device is large-sized, and use of increased transportation mechanism parts for connecting the chambers and transporting substrates results in an increase in number of spots where particles are produced. If laser irradiation is carried out with impurities, such as boron, phosphorus, etc., adhering as particles to the substrates, the characteristics of formed transistors are adversely affected. In applying a laser to the substrates in the vacuum atmosphere or nitrogen atmosphere, moreover, the crystal grain size of non-single crystalline silicon is reduced and the mobility of the transistor characteristics is lowered unless the oxygen concentration of the atmosphere is adjusted to a given value. Furthermore, large quantities of gases are needed to define a predetermined atmosphere, such as a nitrogen atmosphere, in a large-sized chamber for preheating, as well as for annealing, thus entailing an increase in manufacturing costs.